Retrospective studies have confirmed that at least 60% of contrast-associated nephropathy occurs in subjects with chronic renal failure. The incidence approaches 20% in those with a baseline creatinine greater than 198.2 μmol per liter (2.25 mg/dL). Diabetes, in the absence of renal insufficiency, does not appear to confer added risk; however diabetic patients with chronic renal failure are at highest risk. It is particularly this group that develops oliguric renal failure requiring temporary or permanent renal replacement therapy. In diabetic patients with mild to moderate renal failure, the incidence of contrast-associated nephropathy has been reported to be between 9% and 40% however a greater then 50% incidence has been noted in diabetic patients with more severely impaired renal function.